the oriental languages, adds a perfect knowledge of the almost forgotten tongue of his own land. The peculiar tact with which he has destroyed these several suppositions, shows to what perfection the discriminating powers of the human mind may be brought by a constant and vigorous exercise. Their situations, the local customs of Ireland, her traditions, and the derivations and corruptions of the names still given to them by the peasantry, are all brought to bear upon the point with a patience and industry that enthusiasm would have shrunk from, and which nothing but the pure and ardent love of truth could have supported. "Every lover of Ireland, every defender of its polished antiquity, owes a debt of gratitude to our author for the satisfactory and indisputable establishment of its honourable claims. Montmorency's objections against the antiquity of the Round Towers are, to use O'Brien's own expression, dissipated into thin air the authorities of the Greek and Latin authors on whom he relied, shown to be valueless; and the identity of the country with the Insula Hyperboreorum of Hecatæus completely proved." After this, I need not extract the flattering commendations with which this critic concludes, and whose opinions, let me add, by no means stand alone. HENRY O'BRIEN. REMARKS ON SIR CHARLES BELL'S OBJECTIONS AGAINST THE UNDULATORY THEORY OF LIGHT IN HIS BRIDGEWATER TREATISE. MR. URBAN, Cambridge, Sept. 8. SIR Charles Bell observes, "I cannot be satisfied with the statement that light and colours result from vibrations which vary from 458 million of millions to 727 million of millions in 1", when I find that a fine needle pricking the retina will produce brilliant light, and the pressure of the finger on the ball of the eye, will give rise to all the colours of the rainbow." -p. 174. "The retina is subject to exhaustion. When a coloured ray of light impinges continuously on the same part of the retina, it becomes less sensible to it, but more sensible to a ray of the opposite colour."-p. 284. "It appears natural to suppose that if the fibres of the nerve were moved like the chords of a musical instrument by vibrations, they would most easily be kept in motion by undulations' in the same time. If the colour of a red ray depends on the peculiar undulation, before a green ray can produce a motion corresponding to itself, it must encounter a certain opposition in interrupting the motion already begun." -p. 285. The author seems here to suppose that, in order to distinct vision, all the fibres of the nerve (presuming such to exist) must necessarily be put in motion by every individual coloured ray which impinges on the retina, which is a groundless assumption wholly unsupported by proofs. Analogy would lead us to infer the direct contrary. It is an undisputed fact, that particular nerves are susceptible only of particular impressions, each having its own peculiar sensibility, and adaptation to its proper function, its affections from external causes being different from and incommunicable to any other. The nerve of vision is as insensible to touch as the nerve of touch is to light. * What absurdity is there then in extending this hypothesis to the case of those nerves which form the inner fibrous coating or retina of the eye; and conceiving that one fibre may have an oscillatory motion communicated to it by vibrations of light of a certain rapidity, which would not affect another? We observe that in stringed instruments each chord acquires a sympathetic vibration by the impact of the particular note or sound to which it is attuned, and of which alone it is the medium, whether proceeding from a bell or musical glass, or in any other way whatever, and that such vibration results from the impinging of that particular sound and no other, i. e. from the impulse of a certain undulation of air taking place in a given time. And is there any thing absurd à priori, or contrary to physical experience, in conceiving that the nerves of the retina are similarly attuned as it were to particular undulations of light of given velocity, i. e. to particular coloured rays, conveying respectively through the sensorium to the mind, the ideas of red, yellow, ments? blue, and all the intermediate relations theory to be 727 million of millions of vibrations in 1". And this I conceive would sufficiently explain the necessity which we find continually to shift the position of the eye, instead of fixedly and steadily directing the axis towards an object which we wish to see distinctly, and would account for the dimness of vision experienced by the sportsman, who, after marking down his covey, travels with fixed eye towards the spot. p. 284. If it were true that the sound of a musical note became more distinct in proportion to the number of times the string was struck, then perhaps we might be justified in conjecturing from analogy that the same would hold in the organ of seeing as in that of hearing. For it must be presumed that in the organ of hearing, as well as in that of sight, there is some internal structure of visible or invisible nerves, attuned to particular individual sounds. So that each is susceptible of only one particular undulation of air; otherwise we shall find it difficult to account for the variety of sounds which the ear conveys to the mind. But this is not the case. We do not find that the distinctness of a sound is at all commensurate with the number of repetitions; though it may depend on the strength with which the chord was struck, or the initial force of propagation of the air; just as distinctness of vision is dependent upon the force of the undulation which the visible object is capable of propagating to the other; at least to a certain extent, not sine limite, for confusion is as much the effect of too much sound as of too much light. That the eye therefore becomes less sensible to distinct vision, by continuing to look fixedly upon an object, must not be considered a sufficient argument to invalidate our belief of the undulatory theory, resting as it does upon the incontestible evidence of so vast a multiplicity of phænomena in optics, which admit of no explanation upon any other hypothesis. As to the fact of a fine needle producing brilliant light by pricking the retina, and the pressure of the finger on the ball of the eye, giving rise to all the colours of the rainbow, however difficult such phænomena may be to explain, it is clear that they contain no stronger argument against the undulatory theory than against the theory of emission, inasmuch as we can assign no better reason for them on the one theory than on the other; though perhaps either would admit of a sufficiently plausible conjecture of the cause of these appearances. But into this I am not now concerned to inquire. In making these remarks, it was not my intention to enter upon a review of the whole of Sir C. Bell's Treatise, a work of considerable merit, and containing much valuable information. Nor indeed to touch upon any part, but such as was immediately connected with the undulatory theory of light. I cannot, however, dismiss these observations, without briefly adverting to the strange opinion which Sir Charles seems to entertain of the mode in which the mind takes notice of the position of a visible object. Suppose," he says, "a star to be seen by a mariner in the Heavensmust he not, in order to ascertain the position of the star, find out some other object of comparison?" To which I reply, that, if the mariner were required to find a star in the Heavens by the astronomically calculated place, it would undoubtedly be necessary for him to make use of other known stars as objects of comparison, in order to fix and determine it. But when once the star is seen, its position is ascertained already; the seeing of the star being immediately consequent upon the discovering its position. Had the author laid down that, in order to define and demonstrate the position of a star, we must find out some other object of comparison, the assertion had been incontrovertible. But that this was not his meaning is evident from what follows. "We find even mathematicians affirming, that we judge of the direction of an object by the ray which falls on the retina, and the line in which it comes to the eye. But the ray which is here spoken of strikes a mere part of the retina-this point can have no direction." No, but two parts may determine direction, and the two points in this case are the part of the retina struck, and the part in the object from which the impinging ray or undulation proceeds. The line joining these parts manifestly GENT, MAG. VOL. II. determines the direction of the ray. What is meant here by the direction of an object I do not well understand, unless it be intended to signify the direction of the ray emanating from the object. An object can have no direction unless it be in motion, which I hardly think to have been contemplated here. However, even if the word be taken in this sense-the mind would have no more difficulty in ascertaining the direction of a body's motion, by merely considering the angle which the line of its motion makes with the line joining its initial place with the eye, than in ascertaining its fixed position; though it must be confessed, that, in order to define this direction, or demonstrate the particular quarter to which it tends, and the angle it makes with the horizon, there is necessity of establishing a relation to certain known co-ordinates. MR. URBAN, F. S. W. Aug. 8. IN the accompanying sketch I have endeavoured to give a correct representation of an ancient cross, which stands in the church-yard of the picturesque village of Nevern in Pembrokeshire, close by the church-porch (see the Plate). It is a single stone of a quadrangular form, about two feet broad, eighteen inches thick, and thirteen feet high. It is sunk in the earth upwards of seven feet, for excavations to that depth have been made, and the base was still undiscovered. The carving on every side exhibits a variety of knot-work, no two compartments of which resemble each other, and about the middle of the front here represented, are the very imperfect remains of an inscription. The size of the letters is too large to admit of their being more than initial, but what they were can be left only to conjecture. From the sketch they would appear to be Hebrew rather than British or Roman; but the mutilation of time or accident has effected this apparent transformation. In many parts of this county are similarly carved upright stones, but none so perfect as this, either with respect to the knot-work or its cruciform termination. There is one in the church-yard of the village of Bridell, about three miles from Car3 B digan; but this is only imperfectly sculptured, a circular hieroglyphic being only apparent, and this discoverable more by the hand than the eye. Whether the latter is a druidical remain and unconnected with Christianity, I cannot determine, and the emblems inscribed on it are of too vague a character to impress one with any degree of certainty. We cannot however fall into the mistake of a traveller in this part of Wales, whose imagination teemed with druidical recollections and anticipations, and who fancied that in every rubbing stone (and they are in almost every field) he saw some confirmation of their obsolete worship. Perhaps some of your correspondents may be able and willing to direct an inquirer in his search after the origin of these interesting remains? I am, yours, &c. DUDLEY COSTELLO. MR. URBAN, Aug. 10. THE ecclesiastical mint of Durham having enabled the late Mr. Bartlett to appropriate the coins of our three first Edwards, I propose to try, by the assistance of the mint of the Archbishops of York, to establish an earlier coinage of Henry VII. than that usually attributed to him. Snelling says, "that the money coined by this king before he changed the type of it in his 18th year, differs from that of the three preceding Henries in the crown having an arch on it instead of being open, which peculiar type has heretofore been assigned to Henry VI." We have a penny of Edward IV. with the letter T on the right side of the head, and a key on the left side, (see the Plate, Fig. 1.) which reads, "EDWARD D GRA REX ANGL," "CIVITAS EBORACI," which I conceive must have been issued from the mint of Archbishop Rotherham, who was translated from Lincoln to York, in the year 1480. In corroboration of this appropriation, there is a penny of Richard III. (very lately discovered) which (see Fig 2.) has the letter T and the key placed similarly to that of Edward, and reads, "RICARD DI GRA REX ANG," "CIVITAS EBORACI." This coin in my opinion can belong to no other than Rother ham, he having been archbishop during the whole of the reign of Richard III. The penny that I propose to establish as of Henry VII. is one from the same mint, of the same type, same letter and emblem, has an open crown, and reads, "HENRIC DEI GRA REX ANG.""CIVITAS EBORACI," mint-mark a rose. (Fig. 3.) Allowing this coin therefore to proceed from Rotherham's mint, of which I conceive there is no doubt, it must of necessity belong to Henry VII. Rotherham not having been Archbishop until nine years after the death of Henry VI. and having held the see six years after the accession of Henry VII. If these facts be correct, we have a proof of an earlier coinage than the one mentioned by Snelling, and likewise a proof positive that Henry VII. was the first monarch who placed the arch over the crown on his coins. Not one of these curious pennies is published, as far as I know; I have therefore sent you a rude sketch of each, (see the Plate) in the hope of affording some amusement to your numismatic readers, and an inducement to further inquiry. Yours, &c. MR. URBAN, I. D. C. IT is rightly observed by Dr. Laurence, in his preface to the translation of the apocryphal book of ENOCH, that the fate of such writings has been singular, since they have sometimes been injudiciously admitted into the canon of Scripture, and on the other hand, "not simply rejected, but loaded with every epithet of contempt and obloquy." But can we agree with him, in acknowledging that there is such a thing as "an over-anxiety to preserve that canon inviolate?" Perhaps if he were publishing a second edition, he would re-consider that expression. In fact, it is impossible to separate the idea of an inviolate canon from that of inspiration; since if inspiration be contended for, the most rigid scrutiny must be exercised; while, if the point of inspiration be conceded, there can be no canon, in the strict sense of that term, and all the productions of Hebrews and primitive Christians will then have a right to be classed in their respective Scriptures. The real use of apocryphal volumes is to supply testimonies to historical facts, and, as Dr. Laurence observes, to "indicate the theological opinions of the periods at which they were composed." With this view, Mr. Urban, I consider this and similar volumes worthy of studious inspection, as they may often help to elucidate a Scriptural phrase, or to establish the prevalence of a doctrine at certain periods. The following remarks are put forward with the less diffidence, because the learned editor has generally abstained from making annotations, except with regard to the Trinity and the person of Christ. He considers the works to have been composed by a Jew, under the name of Enoch, a few years before the rise of Christianity, and perhaps at an early period of the reign of Herod. His reasoning is, I think, conclusive. And there appears to be good ground for supposing that the author was a descendant of the ten tribes residing in India. I would add, that, presuming the date to be correct, the work is probably a result of that impulse which the expectation of the Messiah's speedily coming communicated not only to the Jews, but also to other nations. Ch. vi. v. 9. 10. The elect shall possess light, joy, and peace; and they shall inherit the earth. But you, ye unholy, shall be accursed.-Conf. Matt. v. 5. The meek shall inherit the earth. It seems from the context that the present world is meant. Perhaps the phrase is equivalent to saying, they only can be said to live. Ch. vii. v. 2. a detailed account of the union of angels with the daughters of men. Conf. Genesis vi. 2. There are so many traditions on this subject in the East, as could surely not have originated from a mere misapprehension of a verse in the Hebrew Scriptures. For my own part, I confess I am inclined to believe that there is some foundation for this opinion, because the testimonies are numerous and explicit. One curious result from the discovery of this book, is, that the fall of angels, mentioned by Peter and Jude, is not anterior to the creation but subsequent to it, in the opinion of the Jews. Ch. ix. v. 3. Thou art Lord of lords, God of gods, King of kings. So Deut. x. 17. The Lord your God is God of gods, and Lord of lords. In Rev. xvii. 14. this expression is altered to Lord of lords, and King of kings. In fact, how could Christ be consistently denominated God of gods, when idolatry is supposed to be worn out? In the days of Moses, when it was prevalent, the Israelites are properly reminded that Jehovah is greater than the pretended deities of the nations. Ibid. The throne of thy glory is for ever and ever. Conf. Hebrews, i. 8. Thy throne, O God, is for ever and ever, addressed to the Son. Ch. xxxi. v. 5. Then holy Raphael, an angel who was with me, answered and said; This is the tree of knowledge, of which thy ancient father and thy widowed mother eat, who were before thee; and who, obtaining knowledge, their eyes being opened, and knowing themselves to be naked, were expelled from the garden. It is remarkable, that nothing material is added here to the narrative in Genesis; whence it is evident, that it was literally understood, for else this apocryphal writer would have enlarged and mystified upon it ad infinitum. In engravings, the tree of knowledge is usually represented as an apple-tree; but such was not the opinion of the Jews, for at verse 4, we are told, it was like a species of the tamarind tree, bearing fruit which resembled grapes extremely fine; and its fragrance extended to a considerable distance. Ch. xxxviii. v. 2. It would have been better for them, had they never been born. Conf. Matt. xxvi. 24. where it is applied to Judas. Much has been written about the import of this phrase. This passage seems to determine the sense, for it is an answer to the question; where will the habitation of sinners be, and the place of rest for those who have rejected the Lord of spirits? I need hardly add, that the writer is speaking of the last judgment. Ch. xl. v. 6. The third voice I heard petitioning and praying for those who dwell on the earth. This petitioner is no other than Gabriel. Although a |